Are all dlp rptv prone to the rainbow and dithering effect?

Discussion in 'Displays' started by Todd smith, Dec 4, 2004.

  1. Todd smith

    Todd smith Supporting Actor

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    I have a Tosh 52hm84 dlp rptv that I have had about a week and am considering returning because of the dithering, rainbow thing that is going on. If I get a fast camera pan or a quick turn of the face, the face of the actor dithers and disintigrates. This is the only way I know to describe this. I was thinking of trying the jvc dila set as it is a 3 chip design and should not have this problem.

    The reason for this message is that I just talked to a salseman at soundtrack who says there hd2+ dlp (same chip as my Tosh) do not do any rainbow effects and it must be my Toshiba. They sell samsung and Mits. I would think any set with the hd2+ chip is going to have similar hickups, in this case rainbows or dithering whatever I am seeing. Is this true or is this isolated to my Tosh? The set does this through component and hdmi and with a cheap dvd player as well as a good one (denon 3910). Would the jvc be a better choice?
     
  2. Allan Jayne

    Allan Jayne Cinematographer

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    All single chip designs whether DLP/DILA/LCOS or RPTV/FPTV will have rainbowing that some people may notice more than other people do. There exist three chip no-color-wheel DLP sets, which are way up in price so we don't hear much about them.

    Not sure about obtrusive visible dithering, but DLP vibrates the tiny mirrors with varied duty cycle to achieve gray scale (light dark dithering within each pixel position) because the mirrors have only two physical tilt positions, aim the light through the optics for white or aim the light off somewhere else for black with a separate "black and white" pattern for red, green, and blue content respectively. I suspect that the less expensive DLP's have a slower vibration rate making dithering more noticeable.

    Some single chip designs have a real black and white picture (clear segment in the color wheel) included with each red, green, blue picture content sequence which many people find reduces the rainbow effect.

    Video hints:
    http://members.aol.com/ajaynejr/video.htm
     

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